ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Background & objectives: Myelolipoma is a rare disease and benign mesenchymal tumour, usually found in the adrenal region. Extra adre- nal sites of this entity are uncommon. Patient are usually asymptomatic. We aim to analyse clinical and pathological aspects of a presacral myelolipoma. Methods: We report a case of presacral myelolipoma in a 62 year- old woman which was initially misdiagnosed as a liposarcoma. This case was diagnosed in our institution in 2022. Results: The Patient presented with atypical coccygeal pain evolving for five years. Patient’s comorbidities consisted of hypertension. Physi- cal examination revealed an abdominal tenderness in the right iliac foss. Magnetic resonance imaging of the pelvis showed a presacral mass measuring 5x3.5x2 cm with fatty and solid components, sugges- tive of a liposarcoma. Thus, patient underwent surgical resection of the mass. Histological examination of the resected mass revealed mature adipose tissue with prominent cellular stroma that was consisted of all three hematopoietic cell lineages ; myeloid, erythroid, and megakaryo- cytic forming cell lines without any evidence of dysplasia. Therefore, the diagnosis of myelolipoma was made. Conclusion: Presacral myelolipoma is an uncommon disease consisting of adipose tissue and hematopoietic cells, easily con- fused with both primary and secondary malignant retroperitoneal tumours. In fact, it still remains a diagnosis challenge for clinicians to make the distinction between liposarcoma and myelolipoma based only on imaging features. E-PS-22-027 An old calcifying aponeurotic fibroma C. Padrão*, M.B. Pimentão, M.A. Cipriano *Hospital Prof. Dr. Fernando Fonseca, Portugal Background & objectives: Calcifying aponeurotic fibroma is a rare, benign fibroblastic tumour more frequent in male children usually in hands and feet. We report a case of a 9 years-old female with a calcifying aponeurotic fibroma with 8 years of evolution. Methods: At the age of 3 years the patient was referenced to the paediatric orthopaedic consultation for a mass in plantar surface of the second finger of the right foot with 2 years of evolution, the patient lost follow up and returned at the age of 7 with a size increase, complain of discomfort walking barefoot and tenderness with palpation. Results: Sequential evaluation at 7 and 8 years old of the foot magnetic resonance imaging showed densification in the plantar, medial, and lateral aspects of the second finger at the proximal phalange of the right foot level. The tendons and the bone were unaffected. The lesion increased in size between the two exams. An excisional biopsy was performed and revealed an infiltrative proliferation through the adipose tissue of ovoid to spindle fibro- blasts in a storiform to fascicular pattern. It also forms a palisade around the nodular areas of chondroid and calcified metaplasia The stroma is collagenous with slit like vascular spaces. Rare osteo- clast-type giant cells are present. Conclusion: The diagnosis of calcifying aponeurotic fibroma was made. This is a benign entity, its infiltrative pattern could mimic malignancy, and although it has a high rate of recurrence, aggres- sive treatments should be avoided. Conservative surgery with pres- ervation of function, is recommended. E-PS-22-028 Collagen orientation probed by polarized Raman spectra on 5μm-thick FFPET sections can be readably used for grading meniscal degeneration N. Prokopi, K. Andrikopoulos, A. Soto Beobide, G. Voyiatzis, D. Papachristou* *University of Patras, School of Medicine, Unit of Bone and Soft Tissue, Patras, Greece Background & objectives: To analyse normal and degenerated menisci with Raman methodology on 5μm-thick FFPET sections and correlate Raman findings with histiopathological grade of meniscus degeneration. 27 degenerated and 6 healthy menisci from human knee joints after total knee replacement/meniscectomy were tested. Methods: H&E analysis on FFPE sections to determine the grade of meniscal degeneration. Raman polarization to evaluate collagen fibrils orientation in different levels of the same sections, used for histopathology. Raman spectra were collected in two different polarization geometries, v-HH and v-VV. We calculated mean value of the v-HH/v-VV intensity ratio of two Raman bands, sensitive/ non-sensitive to the molecular orientation. Results: Collagen specific amide I band at 1665 cm−1, has the higher sensitivity dependence on Raman polarization. Mean val- ues of ratio v-HH/v-VV of the 1665cm−1 peak intensity was sig- nificantly higher in healthy, mean ± SD:2.56±0.46, compared to degenerated menisci, mean ± SD:1.85±0.42 (p=0.0014). Mean values of v-HH/v-VV intensity ratio were 2.18 and 1.50 for low and high degenerated menisci, respectively (p<0.0001). The differ- ence of peak intensities in the two laser polarizations is decreased in the degenerated menisci; this difference is diminishing as the degeneration increases. The v-HH/v-VV ratio was also significantly different in low, compared to control/high grade lesions (p=0.036 and p<0.0001, respectively) mirroring their biology and function. Conclusion: Raman analysis can be reliably applied on FFPET sections and thus can be applied on archival tissues on a variety of pathologies, including cancer. Raman analysis on FFPET can serve as an additional, reliable tool for accurate discrimination between normal/degenerated menisci and between menisci with low- and high-grade degeneration. Technically advanced, preferably portable Raman instruments combined with intra-operative histological analyses could provide faster, real-time and reliable data, adding to the decision making algorithm for management of meniscal and other pathologies E-PS-22-029 Intracranial sclerosing epithelioid fibrosarcoma - a rare neo- plasm in an unusual location S. Pedrosa*, F. Moreira, A. Marques, J. Pinheiro *Pathology Department, Centro Hospitalar e Universitário de São João, Portugal Background & objectives: Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon malignant mesenchymal neoplasm, composed of epithelioid fibroblasts in a dense sclerotic stroma. Most cases occur in the extremities and limb girdles of adults. Intracranial location and occurrence in paediatric age are rarely reported. Methods: We herein report a case of a 16 year-old male, admitted due to left hemiparesis. MRI revealed a 42mm extra-axial intrac- ranial mass in the falx cerebri. He underwent surgical resection and neoadjuvant chemo-radiotherapy. Eleven years later, following surgical reconstruction of the scalp defect, he presented with new onset dyspnea, left pleural effusion and subpleural lung nodules, the greatest measuring 43mm. Results: Histology of the intracranial mass resection revealed epithelioid tumour cells disposed in nests and cords within a dense sclerotic hyalinized stroma. Neoplastic cells showed strong and diffuse MUC4 and vimentin immunoreactivity and were S343